I've seen improvements with PFS3 over FFS and SFS, respectively. In particular, YAM loads folders faster and my drawer with hundreds of PNG icons displays more quickly.
One thing I have noticed, though, is if you enter "version dh0:" against a volume with FFS or SFS you will get the version of the filesystem returned, same if you use Amiga-I on the volume icon. You will not get any return on a PFS3-formatted volume.
I'm not concerned with volume size, at the moment. I have an 18GB SCSI drive in my system and use SMBFS to map a shared drive from a box running RAID. That 18GB drive is obnoxiously loud so I may replace it at some point with a reasonably sized CF with an IDE-to-SCSI or one of those SCSI-CF I've seen floating around.
